EFFECT OF VITAMIN-B6 SUPPLEMENTATION IN MCARDLES-DISEASE - A STRATEGIC CASE-STUDY

A patient-blind study into the effect of a 10-week cessation of long-t erm vitamin B6 supplementation on B6 status and performance in McArdle 's disease is reported. Muscle performance was assessed both subjectiv ely and objectively by an ischaemic fatiguing protocol of the adductor pollicis muscle. Nine weeks after withdrawal of supplementation, vita min B6 status had changed from adequacy to inadequacy and the force lo ss during the ischaemic fatiguing protocol had increased at all freque ncies studied. The patient reported decreased exercise tolerance after 7 weeks and by the tenth week was experiencing an increase in muscle cramps. Vitamin B6 status and muscle performance may be linked in McAr dle's disease and there is potential for enhancement of performance by B6 supplementation. (C) 1998 Elsevier Science B.V.